The Proteomics Core C, working in collaboration with the Genomics and Proteomics Core Laboratory (GPCL) of the University of Pittsburgh, will provide standard and developmental proteomic research services to the investigators within the NK/DC Program Project. Core investigators and staff will provide scientific and technical proteomics expertise to develop and validate new project specific methods and protocols and interact with project investigators in order to coordinate and utilize the available instrumentation in the University of PittsburghlUPCI Basic Genomics and Proteomics Facility (BGPF) and Clinical Proteomics Facility (CPF) in an efficient manner. This efficiency is developed through matching research aims with appropriate state-of-the-art technologies and instrumentation, validated methods and primary data analysis in the Core. The specific set of Core C proteomic technologies and services required within the NK/DC Program include: 1) Ciphergen ProteinChip SELDI-TOF-MS protein expression profiling, 2) Difference Gel Electrophoresis (DiGE), protein labeling, spot picking and tryptic digestion, and 3) LC MS/MS and MALDI MS/MS for profiling and protein identification. The Specific Aims of the Core are to: 1) Design and utilize ProteinChip SELDI-TOF-MS and DiGE and methods to profile complex protein mixtures to monitor biological states and identify important proteomic differences in cultured cells and supernatants, human and mouse sera, PBMCs, and tissue, 2) Utilize high performance mass spectrometry, LC MS/MS and MALDI MS/MS, to obtain the identity of biologically important proteins revealed in the profiling studies, 3) Provide access to tools and expertise in data analysis and interpretation for all analyses.